Hysteretic Model Implementation

See this page for the documentation of this contact model.

contactmodelhysteretic.h

  1#pragma once
  2// contactmodelhysteretic.h
  3
  4#include "contactmodel/src/contactmodelmechanical.h"
  5
  6#ifdef HYSTERETIC_LIB
  7#  define HYSTERETIC_EXPORT EXPORT_TAG
  8#elif defined(NO_MODEL_IMPORT)
  9#  define HYSTERETIC_EXPORT
 10#else
 11#  define HYSTERETIC_EXPORT IMPORT_TAG
 12#endif
 13
 14namespace cmodelsxd {
 15    using namespace itasca;
 16
 17    class ContactModelHysteretic : public ContactModelMechanical {
 18    public:
 19        enum PropertyKeys { kwHzShear=1
 20                          , kwHzPoiss                            
 21                          , kwFric   
 22                          , kwHzF
 23                          , kwHzS
 24                          , kwHzSd
 25                          , kwHzAlpha
 26                          , kwDpMode
 27                          , kwDpEn
 28                          , kwDpEnMin
 29                          , kwDpF 
 30                         };
 31       
 32        HYSTERETIC_EXPORT ContactModelHysteretic();
 33        HYSTERETIC_EXPORT ContactModelHysteretic(const ContactModelHysteretic &) noexcept;
 34        HYSTERETIC_EXPORT const ContactModelHysteretic & operator=(const ContactModelHysteretic &);
 35        HYSTERETIC_EXPORT void   addToStorage(poly::vector<ContactModelMechanical> *s,int ww = -1) override;
 36                         
 37        HYSTERETIC_EXPORT virtual ~ContactModelHysteretic();
 38        virtual void                copy(const ContactModel *c) override;
 39        virtual void                archive(ArchiveStream &); 
 40  
 41        virtual QString  getName() const { return "hysteretic"; }
 42        virtual void     setIndex(int i) { index_=i;}
 43        virtual int      getIndex() const {return index_;}
 44      
 45        virtual QString  getProperties() const { 
 46            return "hz_shear"
 47                   ",hz_poiss"
 48                   ",fric"
 49                   ",hz_force"
 50                   ",hz_slip"
 51                   ",hz_mode"
 52                   ",hz_alpha"
 53                   ",dp_mode"
 54                   ",dp_en"
 55                   ",dp_enmin"
 56                   ",dp_force"
 57            ;
 58        }
 59  
 60        enum EnergyKeys { kwEStrain=1,kwESlip,kwEDashpot};
 61        virtual QString  getEnergies() const { return "energy-strain,energy-slip,energy-dashpot";}
 62        virtual double   getEnergy(uint32 i) const;  // Base 1
 63        virtual bool     getEnergyAccumulate(uint32 i) const; // Base 1
 64        virtual void     setEnergy(uint32 i,const double &d); // Base 1
 65        virtual void     activateEnergy() { if (energies_) return; energies_ = NEW Energies();}
 66        virtual bool     getEnergyActivated() const {return (energies_ !=0);}
 67        
 68        enum FishCallEvents { fActivated=0, fSlipChange};
 69        virtual QString  getFishCallEvents() const { return "contact_activated,slip_change"; }
 70        virtual QVariant getProperty(uint32 i,const IContact *) const;
 71        virtual bool     getPropertyGlobal(uint32 i) const;
 72        virtual bool     setProperty(uint32 i,const QVariant &v,IContact *);
 73        virtual bool     getPropertyReadOnly(uint32 i) const;
 74        
 75        virtual bool     supportsInheritance(uint32 i) const; 
 76        virtual bool     getInheritance(uint32 i) const { assert(i<32); uint32 mask = to<uint32>(1 << i);  return (inheritanceField_ & mask) ? true : false; }
 77        virtual void     setInheritance(uint32 i,bool b) { assert(i<32); uint32 mask = to<uint32>(1 << i);  if (b) inheritanceField_ |= mask;  else inheritanceField_ &= ~mask; }
 78                
 79        virtual uint32     getMinorVersion() const;
 80        
 81        virtual bool    validate(ContactModelMechanicalState *state,const double &timestep);
 82        virtual bool    endPropertyUpdated(const QString &name,const IContactMechanical *c);
 83        virtual bool    forceDisplacementLaw(ContactModelMechanicalState *state,const double &timestep);
 84        virtual DVect2  getEffectiveTranslationalStiffness() const { return effectiveTranslationalStiffness_;}
 85        virtual DAVect  getEffectiveRotationalStiffness() const { return DAVect(0.0);}
 86        
 87        virtual ContactModelHysteretic *clone() const override { return NEW ContactModelHysteretic(); }
 88        virtual double              getActivityDistance() const {return 0.0;}
 89        virtual bool                isOKToDelete() const { return !isBonded(); }
 90        virtual void                resetForcesAndMoments() { hz_F(DVect(0.0)); dp_F(DVect(0.0));  if (energies_) energies_->estrain_ = 0.0;}
 91        virtual void                setForce(const DVect &v,IContact *) { hz_F(v); }
 92        virtual void                setArea(const double &) { throw Exception("The setArea method cannot be used with this contact model."); }
 93        virtual double              getArea() const { return 0.0; }
 94
 95        virtual bool     checkActivity(const double &gap) { return gap <= 0.0; }
 96        
 97        virtual bool     isSliding() const { return hz_slip_; }
 98        virtual bool     isBonded() const { return false; }
 99        virtual void     propagateStateInformation(IContactModelMechanical* oldCm,const CAxes &oldSystem=CAxes(),const CAxes &newSystem=CAxes());
100        virtual void     setNonForcePropsFrom(IContactModel *oldCM);
101        
102        const double & hz_shear() const {return hz_shear_;}
103        void           hz_shear(const double &d) {hz_shear_=d;}
104        const double & hz_poiss() const {return hz_poiss_;}
105        void           hz_poiss(const double &d) {hz_poiss_=d;}
106        const double & fric() const {return fric_;}
107        void           fric(const double &d) {fric_=d;}
108        uint32           hz_mode() const {return hz_mode_;}
109        void           hz_mode(uint32 i) {hz_mode_=i;}
110        const DVect &  hz_F() const {return hz_F_;}
111        void           hz_F(const DVect &f) { hz_F_=f;}
112        bool           hz_S() const {return hz_slip_;}
113        void           hz_S(bool b) { hz_slip_=b;}
114        const double & hz_alpha() const {return hz_alpha_;}
115        void           hz_alpha(const double &d) {hz_alpha_=d;}
116        int            dp_mode() const {return dp_mode_;}
117        void           dp_mode(int i) {dp_mode_=i;}
118        const double & dp_en() const {return dp_en_;}
119        void           dp_en(const double &d) {dp_en_=d;}
120        const double & dp_enmin() const {return dp_enmin_;}
121        void           dp_enmin(const double &d) {dp_enmin_=d;}
122        const DVect &  dp_F() const {return dp_F_;}
123        void           dp_F(const DVect &f) { dp_F_=f;}
124        const double & hn() const {return hn_;}
125        void           hn(const double &d) {hn_=d;}
126        const double & hs() const {return hs_;}
127        void           hs(const double &d) {hs_=d;}
128        const double & vni() const {return vni_;}
129        void           vni(const double &d) {vni_=d;}
130        double         pfac() const {return pfac_;}
131        void           pfac(int i) {pfac_=i;}
132                
133        bool    hasEnergies() const {return energies_ ? true:false;}
134        double  estrain() const {return hasEnergies() ? energies_->estrain_: 0.0;}
135        void    estrain(const double &d) { if(!hasEnergies()) return; energies_->estrain_=d;}
136        double  eslip() const {return hasEnergies() ? energies_->eslip_: 0.0;}
137        void    eslip(const double &d) { if(!hasEnergies()) return; energies_->eslip_=d;}
138        double  edashpot() const {return hasEnergies() ? energies_->edashpot_: 0.0;}
139        void    edashpot(const double &d) { if(!hasEnergies()) return; energies_->edashpot_=d;}
140        
141        uint32 inheritanceField() const {return inheritanceField_;}
142        void inheritanceField(uint32 i) {inheritanceField_ = i;}
143        
144        const DVect2 & effectiveTranslationalStiffness()  const          {return effectiveTranslationalStiffness_;}
145        void           effectiveTranslationalStiffness(const DVect2 &v ) {effectiveTranslationalStiffness_=v;}
146  
147        /// Return the total force that the contact model holds.
148        virtual DVect    getForce() const;
149
150        /// Return the total moment on 1 that the contact model holds
151        virtual DAVect   getMomentOn1(const IContactMechanical *) const;
152
153        /// Return the total moment on 1 that the contact model holds
154        virtual DAVect   getMomentOn2(const IContactMechanical *) const;
155        
156        virtual DAVect getModelMomentOn1() const;
157        virtual DAVect getModelMomentOn2() const;
158
159        // Used to efficiently get properties from the contact model for the object pane.
160        // List of properties for the object pane, comma separated.
161        // All properties will be cast to doubles for comparison. No other comparisons
162        // are supported. This may not be the same as the entire property list.
163        // Return property name and type for plotting.
164        void objectPropsTypes(std::vector<std::pair<QString,InfoTypes>> *) const override;
165        // All properties cast to doubles - this is what can be compared. 
166        void objectPropValues(std::vector<double> *,const IContact *) const override;
167        
168    private:
169        static int index_;
170        
171        bool   updateStiffCoef(const IContactMechanical *con);
172        bool   updateEndStiffCoef(const IContactMechanical *con);
173        bool   updateEndFric(const IContactMechanical *con);
174        void   updateEffectiveStiffness(ContactModelMechanicalState *state);
175        // inheritance fields
176        uint32 inheritanceField_;
177        
178        // hertz model
179        double      hz_shear_ = 0.0;  // Shear modulus
180        double      hz_poiss_ = 0.0;  // Poisson ratio
181        double      fric_ = 0.0;       // Coulomb friction coefficient
182        DVect       hz_F_ = DVect(0.0);      // Force carried in the hertz model
183        bool        hz_slip_ = false;   // the current sliding state
184        uint32        hz_mode_ = 0;   // specifies down-scaling of the shear force when normal unloading occurs 
185        double      hz_alpha_ = 1.5;  // alpha exponent
186        int         dp_mode_ = 0;   // Damping scheme mode
187        double      dp_en_ = 1.0;     // normal restitution coefficient
188        double      dp_enmin_ = 0.0;  // minimal normal restitution coefficient in default mode
189        DVect       dp_F_ = DVect(0.0);      // Damping Force
190                
191        // energies
192        struct Energies {
193            Energies() : estrain_(0.0), eslip_(0.0),edashpot_(0.0) {}
194            double estrain_;  // elastic energy stored in contact 
195            double eslip_;    // work dissipated by friction 
196            double edashpot_;    // work dissipated by dashpots
197        };
198        Energies *   energies_ = nullptr;    
199                
200        double hn_ = 0.0;                               // normal stiffness coefficient
201        double hs_ = 0.0;                               // shear stiffness coefficient
202        DVect2 effectiveTranslationalStiffness_ = DVect2(0.0);  // effective stiffness
203        double vni_ = 0.0;                              // normal impact velocity
204        double pfac_ = 0.0;                             // previous damping factor
205
206    };
207
208} // namespace cmodelsxd
209// EoF

Top

contactmodelhysteretic.cpp

  1// contactmodelhysteretic.cpp
  2#include "contactmodelhysteretic.h"
  3
  4#include "../version.txt"
  5#include "fish/src/parameter.h"
  6#include "utility/src/tptr.h"
  7#include "shared/src/mathutil.h"
  8
  9#include "module/interface/icontact.h"
 10#include "module/interface/icontactmechanical.h"
 11#include "module/interface/ifishcalllist.h"
 12#include "module/interface/ipiece.h"
 13#include "kernel/interface/iprogram.h"
 14
 15
 16#ifdef HYSTERETIC_LIB
 17#ifdef _WIN32
 18    int __stdcall DllMain(void *,unsigned, void *) {
 19        return 1;
 20    }
 21#endif
 22
 23    extern "C" EXPORT_TAG const char *getName() {
 24#if DIM==3
 25        return "contactmodelmechanical3dhysteretic";
 26#else
 27        return "contactmodelmechanical2dhysteretic";
 28#endif
 29    }
 30
 31    extern "C" EXPORT_TAG unsigned getMajorVersion() {
 32        return MAJOR_VERSION;
 33    }
 34
 35    extern "C" EXPORT_TAG unsigned getMinorVersion() {
 36        return MINOR_VERSION;
 37    }
 38
 39    extern "C" EXPORT_TAG void *createInstance() {
 40        cmodelsxd::ContactModelHysteretic *m = NEW cmodelsxd::ContactModelHysteretic();
 41        return (void *)m;
 42    }
 43#endif // HYSTERETIC_LIB
 44
 45namespace cmodelsxd {
 46
 47    static const uint32 shearMask   = 0x00002;
 48    static const uint32 poissMask   = 0x00004;
 49    static const uint32 fricMask    = 0x00008;
 50
 51    using namespace itasca;
 52
 53    int ContactModelHysteretic::index_ = -1;
 54    uint32 ContactModelHysteretic::getMinorVersion() const { return MINOR_VERSION; }
 55
 56    ContactModelHysteretic::ContactModelHysteretic() : inheritanceField_(shearMask|poissMask|fricMask) {
 57    }
 58    
 59    ContactModelHysteretic::ContactModelHysteretic(const ContactModelHysteretic &m) noexcept {
 60        inheritanceField(shearMask|poissMask|fricMask);
 61        this->copy(&m);
 62    }
 63    
 64    const ContactModelHysteretic & ContactModelHysteretic::operator=(const ContactModelHysteretic &m) {
 65        inheritanceField(shearMask|poissMask|fricMask);
 66        this->copy(&m);
 67        return *this;
 68    }
 69    
 70    void ContactModelHysteretic::addToStorage(poly::vector<ContactModelMechanical> *s,int ww) { 
 71        s->addToStorage<ContactModelHysteretic>(*this,ww);
 72    }
 73
 74    ContactModelHysteretic::~ContactModelHysteretic() {
 75        if (energies_)
 76          delete energies_;
 77    }
 78
 79    void ContactModelHysteretic::archive(ArchiveStream &stream) {
 80        stream & hz_shear_;
 81        stream & hz_poiss_;
 82        stream & fric_;
 83        stream & hz_F_;
 84        stream & hz_slip_;
 85        stream & hz_mode_;
 86        stream & hz_alpha_;
 87        stream & dp_mode_;
 88        stream & dp_en_;
 89        stream & dp_enmin_;
 90        stream & dp_F_;
 91        stream & hn_;
 92        stream & hs_;
 93        stream & vni_;
 94        stream & pfac_;
 95
 96        if (stream.getArchiveState()==ArchiveStream::Save) {
 97            bool b = false;
 98            if (energies_) {
 99                b = true;
100                stream & b;
101                stream & energies_->estrain_;
102                stream & energies_->eslip_;
103                stream & energies_->edashpot_;
104            } else
105                stream & b;
106        } else {
107            bool b(false);
108            stream & b;
109            if (b) {
110                if (!energies_)
111                    energies_ = NEW Energies();
112                stream & energies_->estrain_;
113                stream & energies_->eslip_;
114                stream & energies_->edashpot_;
115            }
116        }
117
118        stream & inheritanceField_;
119        stream & effectiveTranslationalStiffness_;
120    }
121
122    void ContactModelHysteretic::copy(const ContactModel *cm) {
123        ContactModelMechanical::copy(cm);
124        const ContactModelHysteretic *in = dynamic_cast<const ContactModelHysteretic*>(cm);
125        if (!in) throw std::runtime_error("Internal error: contact model dynamic cast failed.");
126
127        hz_shear(in->hz_shear());
128        hz_poiss(in->hz_poiss());
129        fric(in->fric());
130        hz_F(in->hz_F());
131        hz_S(in->hz_S());
132        hz_mode(in->hz_mode());
133        hz_alpha(in->hz_alpha());
134        dp_mode(in->dp_mode());
135        dp_en(in->dp_en());
136        dp_enmin(in->dp_enmin());
137        hn(in->hn());
138        hs(in->hs());
139        vni(in->vni());
140        pfac(in->pfac());
141        if (in->hasEnergies()) {
142            if (!energies_)
143                energies_ = NEW Energies();
144            estrain(in->estrain());
145            eslip(in->eslip());
146            edashpot(in->edashpot());
147        }
148        inheritanceField(in->inheritanceField());
149        effectiveTranslationalStiffness(in->effectiveTranslationalStiffness());
150    }
151
152    QVariant ContactModelHysteretic::getProperty(uint32 i,const IContact *) const {
153        // The IContact pointer may be a nullptr!
154        QVariant var;
155        switch (i) {
156            case kwHzShear:  return hz_shear_;
157            case kwHzPoiss:  return hz_poiss_;
158            case kwFric:      return fric_;
159            case kwHzF:      var.setValue(hz_F_); return var;
160            case kwHzS:      return hz_slip_;
161            case kwHzSd:     return hz_mode_;
162            case kwHzAlpha:  return hz_alpha_;
163            case kwDpMode:    return dp_mode_;
164            case kwDpEn:      return dp_en_;
165            case kwDpEnMin:      return dp_enmin_;
166            case kwDpF:       var.setValue(dp_F_); return var;
167        }
168        assert(0);
169        return QVariant();
170    }
171
172    bool ContactModelHysteretic::getPropertyGlobal(uint32 i) const {
173        switch (i) {
174            case kwHzF: return false;
175            case kwDpF: return false;
176        }
177        return true;
178    }
179
180    bool ContactModelHysteretic::setProperty(uint32 i,const QVariant &v,IContact *) {
181        switch (i) {
182            case kwHzShear: {
183                if (!v.canConvert<double>())
184                    throw Exception("hz_shear must be a double.");
185                double val(v.toDouble());
186                if (val<0.0)
187                    throw Exception("Negative shear modulus (hz_shear) not allowed.");
188                hz_shear_ = val;
189                return true;
190            }
191            case kwHzPoiss: {
192                if (!v.canConvert<double>())
193                    throw Exception("hz_poiss must be a double.");
194                double val(v.toDouble());
195                if (val<=-1.0 || val>0.5)
196                    throw Exception("Poisson ratio (hz_poiss) must be in range (-1.0,0.5] ");
197                hz_poiss_ = val;
198                return true;
199            }
200            case kwFric: {
201                if (!v.canConvert<double>())
202                    throw Exception("fric must be a double.");
203                double val(v.toDouble());
204                if (val<0.0)
205                    throw Exception("Negative fric not allowed.");
206                fric_ = val;
207                return false;
208            }
209            case kwHzSd: {
210               if (!v.canConvert<uint32>())
211                    throw Exception("hz_mode must be 0 or 1.");
212                uint32 val(v.toUInt());
213                if (val >1)
214                    throw Exception("hz_mode must be 0 or 1.");
215                hz_mode_ = val;
216                return false;
217            }
218            case kwHzAlpha: {
219                if (!v.canConvert<double>())
220                    throw Exception("hz_alpha must be a double.");
221                double val(v.toDouble());
222                if (val<0.0)
223                    throw Exception("Alpha exponent (hz_alpha) must be positive.");
224                hz_alpha_ = val;
225                return false;
226            }
227            case kwDpMode: {
228               if (!v.canConvert<int>())
229                    throw Exception("dp_mode must be an integer.");
230                int val(v.toInt());
231                dp_mode_ = val;
232                return false;
233            }
234            case kwDpEn: {
235                if (!v.canConvert<double>())
236                    throw Exception("dp_en must be a double.");
237                double val(v.toDouble());
238                if (val<0.0 || val>1.0)
239                    throw Exception("Restitution coefficient (dp_en) must be in range [0.0,1.0] ");
240                dp_en_ = val;
241                return false;
242            }
243            case kwDpEnMin: {
244                if (!v.canConvert<double>())
245                    throw Exception("dp_enmin must be a double.");
246                double val(v.toDouble());
247                if (val<0.0 || val>1.0)
248                    throw Exception("Minimal restitution coefficient (dp_enmin) must be in range [0.0,1.0] ");
249                dp_enmin_ = val;
250                return false;
251            }
252        }
253        return false;
254    }
255
256    bool ContactModelHysteretic::getPropertyReadOnly(uint32 i) const {
257        switch (i) {
258            case kwHzF:
259            case kwHzS:
260            case kwDpF:
261                return true;
262            default:
263                break;
264        }
265        return false;
266    }
267
268    bool ContactModelHysteretic::supportsInheritance(uint32 i) const {
269        switch (i) {
270            case kwHzShear:
271            case kwHzPoiss:
272            case kwFric:
273                return true;
274            default:
275                break;
276        }
277        return false;
278    }
279
280    double ContactModelHysteretic::getEnergy(uint32 i) const {
281        double ret(0.0);
282        if (!energies_)
283            return ret;
284        switch (i) {
285            case kwEStrain:  return energies_->estrain_;
286            case kwESlip:    return energies_->eslip_;
287            case kwEDashpot: return energies_->edashpot_;
288        }
289        assert(0);
290        return ret;
291    }
292
293    bool ContactModelHysteretic::getEnergyAccumulate(uint32 i) const {
294        switch (i) {
295            case kwEStrain:  return false;
296            case kwESlip:    return true;
297            case kwEDashpot: return true;
298        }
299        assert(0);
300        return false;
301    }
302
303    void ContactModelHysteretic::setEnergy(uint32 i,const double &d) {
304        if (!energies_) return;
305        switch (i) {
306            case kwEStrain:  energies_->estrain_ = d; return;
307            case kwESlip:    energies_->eslip_   = d; return;
308            case kwEDashpot: energies_->edashpot_   = d; return;
309        }
310        assert(0);
311        return;
312    }
313
314    bool ContactModelHysteretic::validate(ContactModelMechanicalState *state,const double &) {
315        assert(state);
316        const IContactMechanical *c = state->getMechanicalContact();
317        assert(c);
318
319        if (state->trackEnergy_)
320            activateEnergy();
321
322        updateStiffCoef(c);
323        if ((inheritanceField_ & shearMask) || (inheritanceField_ & poissMask))
324            updateEndStiffCoef(c);
325
326        if (inheritanceField_ & fricMask)
327            updateEndFric(c);
328
329        updateEffectiveStiffness(state);
330        return checkActivity(state->gap_);
331    }
332
333    bool ContactModelHysteretic::updateStiffCoef(const IContactMechanical *con) {
334        double hnold = hn_;
335        double hsold = hs_;
336        double c12 = con->getEnd1Curvature().y();
337        double c22 = con->getEnd2Curvature().y();
338        double reff = c12+c22;
339        if (reff == 0.0)
340            throw Exception("Hysteretic contact model undefined for 2 non-curved surfaces");
341        reff = 2.0 /reff;
342        hn_ = 2.0/3.0 * (hz_shear_/(1 -hz_poiss_)) * sqrt(2.0*reff);
343        hs_ = (2.0*pow(hz_shear_*hz_shear_*3.0*(1-hz_poiss_)*(reff),1.0/3.0)) / (2.0- hz_poiss_);
344        return ( (hn_ != hnold) || (hs_ != hsold) );
345    }
346
347    static const QString gstr("hz_shear");
348    static const QString nustr("hz_poiss");
349    bool ContactModelHysteretic::updateEndStiffCoef(const IContactMechanical *con) {
350        assert(con);
351        double g1 = hz_shear_;
352        double g2 = hz_shear_;
353        double nu1 = hz_poiss_;
354        double nu2 = hz_poiss_;
355        QVariant vg1 = con->getEnd1()->getProperty(gstr);
356        QVariant vg2 = con->getEnd2()->getProperty(gstr);
357        QVariant vnu1 = con->getEnd1()->getProperty(nustr);
358        QVariant vnu2 = con->getEnd2()->getProperty(nustr);
359        if (vg1.isValid() && vg2.isValid()) {
360            g1 = vg1.toDouble();
361            g2 = vg2.toDouble();
362            if (g1 < 0.0 || g2 < 0.0)
363                throw Exception("Negative shear modulus not allowed in Hysteretic contact model");
364        }
365        if (vnu1.isValid() && vnu2.isValid()) {
366            nu1 = vnu1.toDouble();
367            nu2 = vnu2.toDouble();
368            if (nu1 <= -1.0 || nu1 > 0.5 || nu2 <= -1.0 || nu2 > 0.5)
369                throw Exception("Poisson ratio should be in range (-1.0,0.5] in Hysteretic contact model");
370        }
371        if (g1*g2 == 0.0) return false;
372        double es = 1.0 / ((1.0-nu1) / (2.0*g1) + (1.0-nu2) / (2.0*g2));
373        double gs = 1.0 / ((2.0-nu1) / g1 + (2.0-nu2) /g2);
374        hz_poiss_ = (4.0*gs-es)/(2.0*gs-es);
375        hz_shear_ = 2.0*gs*(2-hz_poiss_);
376        if (hz_shear_ < 0.0)
377            throw Exception("Negative shear modulus not allowed in Hysteretic contact model");
378        if (hz_poiss_ <= -1.0 || hz_poiss_ > 0.5)
379            throw Exception("Poisson ratio should be in range (-1.0,0.5] in Hysteretic contact model");
380        return updateStiffCoef(con);
381    }
382
383    static const QString fricstr("fric");
384    bool ContactModelHysteretic::updateEndFric(const IContactMechanical *con) {
385        assert(con);
386        QVariant v1 = con->getEnd1()->getProperty(fricstr);
387        QVariant v2 = con->getEnd2()->getProperty(fricstr);
388        if (!v1.isValid() || !v2.isValid())
389            return false;
390        double fric1 = std::max(0.0,v1.toDouble());
391        double fric2 = std::max(0.0,v2.toDouble());
392        double val = fric_;
393        fric_ = std::min(fric1,fric2);
394        return ( (fric_ != val) );
395    }
396
397    bool ContactModelHysteretic::endPropertyUpdated(const QString &name,const IContactMechanical *c) {
398        assert(c);
399        QStringList availableProperties = getProperties().simplified().replace(" ","").split(",",Qt::SkipEmptyParts);
400        QRegularExpression rx(name, QRegularExpression::CaseInsensitiveOption);
401        int idx = availableProperties.indexOf(rx)+1;
402        bool ret=false;
403
404        if (idx<=0)
405            return ret;
406
407        switch(idx) {
408            case kwHzShear: {
409                if (inheritanceField_ & shearMask)
410                    ret = updateEndStiffCoef(c);
411                break;
412            }
413            case kwHzPoiss: {
414                if (inheritanceField_ & poissMask)
415                    ret = updateEndStiffCoef(c);
416                break;
417            }
418            case kwFric: {
419                if (inheritanceField_ & fricMask)
420                    ret = updateEndFric(c);
421                break;
422            }
423        }
424        return ret;
425    }
426
427    void ContactModelHysteretic::updateEffectiveStiffness(ContactModelMechanicalState *state) {
428        effectiveTranslationalStiffness_ = DVect2(hn_,hs_);
429        if (state->gap_ >= 0.0) return;
430        double overlap = - state->gap_;
431        double kn = 1.5*hn_*sqrt(overlap);
432        double ks = hs_ * pow(hz_F_.x(),(1.0/3.0));
433        DVect2 ret(kn,ks);
434        effectiveTranslationalStiffness_ = ret;
435    }
436
437    bool ContactModelHysteretic::forceDisplacementLaw(ContactModelMechanicalState *state,const double &timestep) {
438        assert(state);
439        bool firstActive = false;
440        if (state->activated()) {
441            if (cmEvents_[fActivated] >= 0) {
442                auto c = state->getContact();
443                std::vector<fish::Parameter> arg = { fish::Parameter(c->getIThing()) };
444                IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
445                fi->setCMFishCallArguments(c,arg,cmEvents_[fActivated]);
446            }
447            firstActive = true;
448        }
449
450        double overlap = - state->gap_;
451        DVect trans = state->relativeTranslationalIncrement_;
452#ifdef THREED
453        DVect norm(trans.x(),0.0,0.0);
454#else
455        DVect norm(trans.x(),0.0);
456#endif
457
458        //DAVect ang  = state->relativeAngularIncrement_;
459        DVect hz_F_old = hz_F_;
460        hz_F_ = DVect(0.0);
461        dp_F_ = DVect(0.0);
462        double ks_old = hs_ * pow(hz_F_old.x(),(1.0/3.0));
463        DVect fs_old = hz_F_old;
464        fs_old.rx() = 0.0;
465        if (overlap > 0) {
466
467            double kn = 1.5 * hn_ * sqrt(overlap);
468
469            double vn = norm.x() / timestep;
470            if (firstActive) {
471                if (vn <= 0.0)
472                    vni_= vn;
473                else
474                    vni_ = 0.0;
475                fs_old = DVect(0.0);
476                ks_old = 0.0;
477                hz_F_old = DVect(0.0);
478                pfac_ = 0.0;
479            }
480            hz_F_.rx() = hn_*pow(overlap,hz_alpha_);
481
482            double ks = hs_ * pow(hz_F_.x(),(1.0/3.0));
483            effectiveTranslationalStiffness_ = DVect2(kn,ks);
484
485            //damping force
486            if (std::abs(vni_) <= limits<double>::epsilon()*1000.0)
487                dp_F_.rx() = 0.0;
488            else {
489                double ratio = vn/vni_;
490                double fac(0.0);
491                switch (dp_mode_) {
492                default:
493                    {
494                        double used = max(dp_en_,dp_enmin_);
495                        fac = max(0.0,(1.0-used*used)/used)*ratio; //Gonthier et al.
496                    }
497                    break;
498                case 1:
499                    fac = 0.75*(1.0-dp_en_*dp_en_)*ratio; // Lankarani et al (1989).
500                    break;
501                case 2:
502                    fac = 0.75*(1.0-dp_en_*dp_en_)*exp(2.0*(1-dp_en_))*ratio; // Zhiying et al.
503                    break;
504                }
505
506                if (fac <= -1.0) { // sucking
507                    if (pfac_ >= 0.0) { //switch in one timestep from pushing to sucking - instability
508                        fac = 0.0;
509                        pfac_ = 0.0;
510                    } else
511                        pfac_ = fac;
512                } else if (pfac_ != 0.0 && abs(fac) > 10.0*abs(pfac_)) { // growing too fast - instability
513                    fac = 0.0;
514                    pfac_ = 0.0;
515                } else
516                    pfac_ = fac;
517
518                dp_F_.rx() = hz_F_.x()*fac;
519            }
520
521            DVect u_s = trans;
522            u_s.rx() = 0.0;
523            DVect vec = u_s * ks;
524            if (hz_mode_ && (hz_F_.x() < hz_F_old.x())) {
525                double rat = ks / ks_old;
526                fs_old *= rat;
527            }
528            DVect fs = fs_old - vec;
529
530            if (state->canFail_) {
531                // resolve sliding
532                double crit = hz_F_.x() * fric_;
533                double sfmag = fs.mag();
534                if (sfmag > crit) {
535                    double rat = crit / sfmag;
536                    fs *= rat;
537                    if (!hz_slip_ && cmEvents_[fSlipChange] >= 0) {
538                        auto c = state->getContact();
539                        std::vector<fish::Parameter> arg = { fish::Parameter(c->getIThing()),
540                                                             fish::Parameter() };
541                        IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
542                        fi->setCMFishCallArguments(c,arg,cmEvents_[fSlipChange]);
543                    }
544                    hz_slip_ = true;
545                } else {
546                    if (hz_slip_) {
547                        if (cmEvents_[fSlipChange] >= 0) {
548                            auto c = state->getContact();
549                            std::vector<fish::Parameter> arg = { fish::Parameter(c->getIThing()),
550                                                                 fish::Parameter((qint64)1) };
551                            IFishCallList *fi = const_cast<IFishCallList*>(state->getProgram()->findInterface<IFishCallList>());
552                            fi->setCMFishCallArguments(c,arg,cmEvents_[fSlipChange]);
553                        }
554                        hz_slip_ = false;
555                    }
556                }
557            }
558
559            fs.rx() = hz_F_.x();
560            hz_F_ = fs;          // total force in hertz part
561
562            // 5) Compute energies
563            if (state->trackEnergy_) {
564                assert(energies_);
565                energies_->estrain_ =  0.0;
566                if (kn)
567                    energies_->estrain_ = hz_alpha_*hz_F_.x()*hz_F_.x()/((hz_alpha_+1)*kn);
568                if (ks) {
569                    DVect s = hz_F_;
570                    s.rx() = 0.0;
571                    double smag2 = s.mag2();
572                    energies_->estrain_ += 0.5*smag2 / ks;
573                    if (hz_slip_) {
574                        hz_F_old.rx() = 0.0;
575                        DVect avg_F_s = (s + hz_F_old)*0.5;
576                        DVect u_s_el =  (s - hz_F_old) / ks;
577                        energies_->eslip_ -= std::min(0.0,(avg_F_s | (u_s + u_s_el)));
578                    }
579                }
580                energies_->edashpot_ -= dp_F_ | trans;
581            }
582
583        } else {
584            hz_F_ = DVect(0.0);
585            dp_F_ = DVect(0.0);
586            pfac_ = 0.0;
587        }
588
589
590        return true;
591    }
592
593    void ContactModelHysteretic::propagateStateInformation(IContactModelMechanical* old,const CAxes &oldSystem,const CAxes &newSystem) {
594        // Only do something if the contact model is of the same type
595        if (old->getContactModel()->getName().compare("hysteretic",Qt::CaseInsensitive) == 0) {
596            ContactModelHysteretic *oldCm = (ContactModelHysteretic *)old;
597#ifdef THREED
598            // Need to rotate just the shear component from oldSystem to newSystem
599
600            // Step 1 - rotate oldSystem so that the normal is the same as the normal of newSystem
601            DVect axis = oldSystem.e1() & newSystem.e1();
602            double c, ang, s;
603            DVect re2;
604            if (!checktol(axis.abs().maxComp(),0.0,1.0,1000)) {
605                axis = axis.unit();
606                c = oldSystem.e1()|newSystem.e1();
607                if (c > 0)
608                  c = std::min(c,1.0);
609                else
610                  c = std::max(c,-1.0);
611                ang = acos(c);
612                s = sin(ang);
613                double t = 1. - c;
614                DMatrix<3,3> rm;
615                rm.get(0,0) = t*axis.x()*axis.x() + c;
616                rm.get(0,1) = t*axis.x()*axis.y() - axis.z()*s;
617                rm.get(0,2) = t*axis.x()*axis.z() + axis.y()*s;
618                rm.get(1,0) = t*axis.x()*axis.y() + axis.z()*s;
619                rm.get(1,1) = t*axis.y()*axis.y() + c;
620                rm.get(1,2) = t*axis.y()*axis.z() - axis.x()*s;
621                rm.get(2,0) = t*axis.x()*axis.z() - axis.y()*s;
622                rm.get(2,1) = t*axis.y()*axis.z() + axis.x()*s;
623                rm.get(2,2) = t*axis.z()*axis.z() + c;
624                re2 = rm*oldSystem.e2();
625            } else
626                re2 = oldSystem.e2();
627
628            // Step 2 - get the angle between the oldSystem rotated shear and newSystem shear
629            axis = re2 & newSystem.e2();
630            DVect2 tpf;
631            DMatrix<2,2> m;
632            if (!checktol(axis.abs().maxComp(),0.0,1.0,1000)) {
633                axis = axis.unit();
634                c = re2|newSystem.e2();
635                if (c > 0)
636                    c = std::min(c,1.0);
637                else
638                    c = std::max(c,-1.0);
639                ang = acos(c);
640                if (!checktol(axis.x(),newSystem.e1().x(),1.0,100))
641                    ang *= -1;
642                s = sin(ang);
643                m.get(0,0) = c;
644                m.get(1,0) = s;
645                m.get(0,1) = -m.get(1,0);
646                m.get(1,1) = m.get(0,0);
647                tpf = m*DVect2(oldCm->hz_F_.y(),oldCm->hz_F_.z());
648            } else {
649                m.get(0,0) = 1.;
650                m.get(0,1) = 0.;
651                m.get(1,0) = 0.;
652                m.get(1,1) = 1.;
653                tpf = DVect2(oldCm->hz_F_.y(),oldCm->hz_F_.z());
654            }
655            DVect pforce = DVect(0,tpf.x(),tpf.y());
656#else
657            oldSystem;
658            newSystem;
659            DVect pforce = DVect(0,oldCm->hz_F_.y());
660#endif
661            for (int i=1; i<dim; ++i)
662                hz_F_.rdof(i) += pforce.dof(i);
663            oldCm->hz_F_ = DVect(0.0);
664
665            if(oldCm->getEnergyActivated()) {
666                activateEnergy();
667                energies_->estrain_  = oldCm->energies_->estrain_;
668                energies_->eslip_    = oldCm->energies_->eslip_;
669                energies_->edashpot_ = oldCm->energies_->edashpot_;
670                oldCm->energies_->estrain_  = 0.0;
671                oldCm->energies_->eslip_    = 0.0;
672                oldCm->energies_->edashpot_ = 0.0;
673            }
674        }
675    }
676
677    void ContactModelHysteretic::setNonForcePropsFrom(IContactModel *old) {
678        // Only do something if the contact model is of the same type
679        if (old->getName().compare("hysteretic",Qt::CaseInsensitive) == 0 && !isBonded()) {
680            ContactModelHysteretic *oldCm = (ContactModelHysteretic *)old;
681            hn_ = oldCm->hn_;
682            hs_ = oldCm->hs_;
683            fric_ = oldCm->fric_;
684            vni_ = oldCm->vni_;
685            pfac_ = oldCm->pfac_;
686          }
687    }
688
689    DVect ContactModelHysteretic::getForce() const {
690        DVect ret(hz_F_);
691        ret += dp_F_;
692        return ret;
693    }
694
695    DAVect ContactModelHysteretic::getMomentOn1(const IContactMechanical *c) const {
696        DVect force = getForce();
697        DAVect ret(0.0);
698        c->updateResultingTorqueOn1Local(force,&ret);
699        return ret;
700    }
701
702    DAVect ContactModelHysteretic::getMomentOn2(const IContactMechanical *c) const {
703        DVect force = getForce();
704        DAVect ret(0.0);
705        c->updateResultingTorqueOn2Local(force,&ret);
706        return ret;
707    }
708    
709    DAVect ContactModelHysteretic::getModelMomentOn1() const {
710        DAVect ret(0.0);
711        return ret;
712    }
713    
714    DAVect ContactModelHysteretic::getModelMomentOn2() const {
715        DAVect ret(0.0);
716        return ret;
717    }
718
719    void ContactModelHysteretic::objectPropsTypes(std::vector<std::pair<QString,InfoTypes>> *ret) const {
720        ret->clear();
721        ret->push_back({"hz_shear",ScalarInfo});
722        ret->push_back({"hz_poiss",ScalarInfo});
723        ret->push_back({"fric",ScalarInfo});
724        ret->push_back({"hz_force",VectorInfo});
725        ret->push_back({"hz_slip",ScalarInfo});
726        ret->push_back({"hz_mode",ScalarInfo});
727        ret->push_back({"hz_alpha",ScalarInfo});
728        ret->push_back({"dp_mode",ScalarInfo});
729        ret->push_back({"dp_en",ScalarInfo});
730        ret->push_back({"dp_enmin",ScalarInfo});
731        ret->push_back({"dp_force",VectorInfo});
732    }
733    
734    void ContactModelHysteretic::objectPropValues(std::vector<double> *ret,const IContact *) const {
735        ret->clear();
736        ret->push_back(hz_shear_);
737        ret->push_back(hz_poiss_);
738        ret->push_back(fric_);
739        ret->push_back(hz_F_.mag());
740        ret->push_back(hz_slip_);
741        ret->push_back(hz_mode_);
742        ret->push_back(hz_alpha_);
743        ret->push_back(dp_mode_);
744        ret->push_back(dp_en_);
745        ret->push_back(dp_enmin_);
746        ret->push_back(dp_F_.mag());
747    }
748
749} // namespace cmodelsxd
750// EoF

Top